Iron oxide nanoparticles are used to label and track inflammatory and stem cells by MRI [Leor J, Rozen L, Zuloff-Shani A, Feinberg M. S, Amsalem Y, Barbash I M, Kachel E, Holbova R, Mardor Y, Daniels D, Ocherashvilli A, Orenstein A, Danon D. Ex vivo activated human macrophages improve healing, remodeling, and function of the infarcted heart. Circulation. (2006); 114(1 Suppl):194-100].
The most sensitive existing markers for cell labeling using MRI are superparamagnetic iron oxide (SPIO) particles. They are nontoxic and biodegradable and do not affect proliferation and multi-lineage differentiation capacity in vitro.
A review on magnetic iron oxide nanoparticles, including the synthesis and surface funtionalization strategies was provided by Wei Wu et al. [Wei W, He Q, Jiang C. Magnetic Iron oxide nanoparticles: synthesis and surface functionalizing strategies. Nanoscale Res. Lett. (2008); 3: 397-415].
Iron oxide nanoparticles have been described as anti-inflammatory in an in vitro pathogen-induced inflammation model induced by lipopolysaccharides (LPS) [Siglienti I, Bendszus M, Kleinschnitz C, Stoll G. Cytokine profile of iron laden macrophages: Implications for cellular magnetic resonance imaging. J. Neuroimmunology. (2006); 173: 166-173].